1. Field of the Invention
The invention relates generally to carbon nanotube films and, particularly, to a method for making a metal doped carbon nanotube film.
2. Discussion of Related Art
Carbon nanotubes (CNTs) produced by means of arc discharge between graphite rods were first discovered and reported in an article by Sumio Iijima, entitled “Helical Microtubules of Graphitic Carbon” (Nature, Vol. 354, Nov. 7, 1991, pp. 56-58). CNTs are electrically conductive along their length, chemically stable, and capable, individually, of having a very small diameter (much less than 100 nanometers) and large aspect ratios (length/diameter). Due to these and other properties, it has been suggested that CNTs can play an important role in various fields, such as field emission devices, new optic materials, sensors, soft ferromagnetic materials, etc.
Carbon nanotube film has been found especially useful in field emission electron sources, photoelectric and biological sensors, transparent electrical conductors, battery electrodes, absorbing materials, water purification materials, light emitting material, and related devices. As a result of rapid development of fabrication technology of carbon nanotube film, metal and carbon nanotubes are now compounded to form a carbon nanotube film, which is beneficial to exploit the electricity conductivity and the thermal conductivity of the carbon nanotubes therein.
A fabrication method of the carbon nanotube film with metal is generally as follows. Firstly, a carbon nanotube film is prepared in advance. Secondly, metal is spray filled and/or evaporated filled into gaps in the carbon nanotube film to form the carbon nanotube film with carbon nanotube and metal compound. However, the above-described methods generally have complicated fabrication procedures. Thus, in use, such methods have proven less efficient than truly desirable. Furthermore, the carbon nanotube film produced by the above-described methods has the problems, such as a small ratio of metal and the metal unevenly dispersed in the carbon nanotube film.
What is needed, therefore, is a method for making a carbon nanotube film from a carbon nanotube and metal compound, which is very simple and efficient in producing the film and has a controllable ratio of metal uniformly dispersed therein.